Make the Burger Sauce: In a small bowl, combine the mayonnaise, ketchup, mustard, chopped gherkins, and gherkin brine. Stir until well mixed. Set aside. This can be done hours or even a day ahead.

Prepare the Buns and Toppings: Slice your buns in half. Lightly toast the cut sides in a dry pan over medium heat until just golden, for about 1-2 minutes. This stops them from getting soggy later. Set them aside. Have your thinly sliced onion and gherkins ready.

Portion the Mince: Gently divide the mince into 8 equal portions of 100g each. Roll them loosely into balls – do not compact them or overwork the meat. Just shape them lightly. Seasoning comes later.

Heat Your Pan: Place a large, heavy-based frying pan or cast-iron skillet over a high heat. Add the oil or beef dripping. You want the pan to be seriously hot; wait until you see the oil shimmering or the first wisps of smoke.

Smash the Burgers: Working in batches to avoid overcrowding, place two balls of mince into the hot pan, leaving plenty of space between them. Immediately place a square of baking parchment on top of one ball and press down firmly with a sturdy metal spatula for about 10 seconds, creating a thin patty around 1cm thick. Repeat with the second ball.

Sear and Season: Peel off the parchment paper. Season the tops of the patties generously with salt and pepper. Cook for 2-3 minutes, without moving them, until a deep, dark brown crust has formed on the underside. You'll see the edges becoming crispy and brown.

Flip and Add Cheese: Using your sturdy spatula, carefully scrape underneath the patties to ensure you get all of that delicious crust, and flip them over. Immediately place a slice of cheese on top of each patty to melt. Cook for another 1-2 minutes.

Assemble Your Burger: Spread a generous layer of burger sauce on the bottom half of each toasted bun. Place two cheesy patties on top. Add your sliced onions and gherkins. Finish with the top bun and serve immediately. It's a burger that waits for no one! I find that wrapping them in a bit of foil for one minute helps steam the bun and melt everything together perfectly.